The present invention generally relates to computer systems. More specifically the invention relates to dialog arrangements and methods for interrogating a user and taking action relevant thereto.
From the point of view of the user, background systems can often be interpreted as a set of possible actions for whose execution a set of parameters must be known. When operating such systems, the user must inform the system of the action and of the parameters.
Arrangements for action determination, for example information systems, select the soft action on the basis of information that a user gives to the arrangement and implement this action. For determining the information, it is partly necessary to carry out a dialog with the user if the information provided over by the user is inadequate for determining the information that is actually sought.
Various arrangements and methods are known for designing dialogs and, for the corresponding dialog system, which is what an arrangement for determining information upon employment of an additional dialog between the arrangement and the user is called. In J. Markowitz, Using Speech Recognition, Prentice Hall PTR, ISBN 0-13-186321-5, pp. 206-213, 1996 there is disclosed a method for dialog design wherein the respective dialog is modeled with a finite automaton or with predetermined dialog menus as well. A branching tree is thereby produced for each application. The information needed for the branching is obtained by are interrogating the user. It is thereby standard, for example, to establish fixed dialog trees.
An arrangement and a method for dialog design employing a natural language dialog is also disclosed in Goddeau, D., E. Brill, J. Glass, C. Pao, M. Phillips, J. Polifroni, S. Seneff and V. Zue, 1994: GALAXY: A Human-Language Interface to On-line Travel Information. Proc. International Conference on Spoken Language Processing, Yokohama, pp. 1-4. Dialog systems of this type allow the user to formulate his request in everyday language, for example, "I would like to travel today from Munich to Hamburg". In natural language dialog systems, the expression of the user is syntactically and semantically analyzed. The result is a formal semantic representation of the content of the expression. What action the user would like to begin and what parameters he has already named are determined from the semantic representation of the expression. The dialog system determines therefrom what parameters still must be revealed for the implementation of the action and asks a corresponding question, for example, "Would you like to fly or travel by train?". The user's answer is again syntactically/semantically analyzed. The sought parameter is determined from the semantic representation.
In this method or, respectively, dialog system two different approaches are fundamentally distinguished.
Pulman, S. G., H. Alshawi, D. M. Carter, R. S. Crouch, M. Rayner and A. G. Smith, 1993: CLARE: A Combined Language and Reasoning Engine, Proc. of the JFIT conference, pp. 1-8 discloses a method and a dialog system wherein a universal analysis module is employed that, in the ideal case, should be in a position to syntactically and semantically analyze every statement and supply a canonic, semantic representation of the literal significance. What is referred to as a reasoning component is utilized for the dialog design, this, on the one hand, logging the course of the dialog and, on the other hand, determining the parameters that are still needed for the action determination and, further, imaging the canonic, semantic representation onto a potential background application. Methods of knowledge representation and knowledge processing are usually utilized on the background application for imaging the canonic semantic representation.
Goddeau, D., E. Brill, J. Glass, C. Pao, M. Phillips, J. Polifroni, S. Seneff and V. Zue, 1994: GALAXY: A Human-Language Interface to On-line Travel Information. Proc. International Conference on Spoken Language Processing, Yokohama, pp. 1-4 discloses another approach wherein what are referred to as "semantic grammars" are developed for every conceivable user statement, these converting the statement into a semantic representation directly, i.e., without a detour via the syntax analyzer. The dialog design and the imaging onto the background application that is eventually provided usually ensues in the same way as was described above in the method and the dialog system from the Pulman et al. report.
The known methods or, respectively, dialog systems exhibit many disadvantages.
The method or, respectively, dialog system disclosed by J. Markowitz, referred to above, is in fact extremely rugged but exhibits the disadvantage that it allows the user no degrees of freedom whatsoever in dialog management. Over and above this, the entire, existing branching tree must be investigated given an expansion of the dialog system or, respectively, of the method by a new action, and must be potentially redesigned in order to take the new action into consideration at a corresponding location. This denotes a substantial outlay that can incur extremely high costs. For this reason, the J. Markowitz method or, respectively, dialog system is extremely inflexible and can be expanded only given large outlay.
The approach known from the Pulman et al. report exhibits the disadvantage that this approach has not yet succeeded in developing a grammar of a natural language that is in a position to analyze all possible statements of a user. Therefore this method and the dialog system corresponding thereto, is not rugged.
Over and above this, the aging of the generic significance representation onto the background application involves great outlay. This approach, just like the approach described by Goddeau et al., is also extremely complex and, thus, complicated to implement or, respectively, realize, this leading to high costs of both of these approaches. The expandability and, thus, the flexibility in any of these approaches are established to only an extremely limited extent.
It must be taken into consideration in the expandability of a system that a substantial outlay must be invested into the development of the grammars for each new application and these jobs can only be carried out by extremely qualified personnel. The approaches of Goddeau aet al. and Pulman et al. are thus disproportionately complicated for most applications, even though the approach of Goddeau et al. is generally more rugged than the approach of Pulman et al. since only the user expressions possible in the specific application need be taken into consideration in the development of the semantic grammar.